Wildlife and bird anatomy Flashcards
Describe the structures of the head in birds ?
The head of birds is divided into three parts
- neurocranium, splanchnocranium and mandibular
Neurocranium
- single occipital condyle
- very large occipital sockets, good vision
- many sinuses which makes birds prone to infection
Splanchnocranium
- Forms the upper (maxillary) jaw and upper roof of the oral cavity
- includes incisive bone holding upper beak with rod like “pushrods” structure
Mandible
- Consist of two thin bones which are fused rostrally and covered by lower beak
- connect to the skull bewteen quadrate bone and articular bone.
Describe how musculoskeletal system is adapted for flight in birds ?
Adaptation of the musculoskeletal system of birds for flight.
- pneumatice bones
- bone fusions of the appendicular skelton (pectoral limb and wing) providing rigidity and strength
- strong pectoral girdle (unique muscle pulley system)
Describe the pectoral girdle in birds and its adaptation for flight ?
Bird pectoral girdle
Triangulated bones pectoral girdle = acts to stabilise the cranial thorax (Notarium)
The pectoral girdle is composed of three bones
Coracoid - very strong articulates to the sternum
Scapular - tightly bound to the rib cage
Clavicle - fused in the midline (Furcula or wish bone)
The pectoral girdle forms a stable suuport for the wings. The humerus articulates with the scapular and coracoid at the Glenoid fossa.
Disscuss why the neck of birds is so flexible?
The flexability of bird necks
The neck of birds
- one occipital condyle
- multiple cervical vertebrae 8-25 (only 7 in mammals)
- All cervical vertebrae carry cervical ribs, as a caudal spike at the transverse process
- have articular joints making them very flexible
(NO FIBROCARTILAGE DISCS)
Explain why the thorax in birds is fused?
What is this fused thorax called?
Birds’ Notarium = fused vertebrae
- The fused vertebrae of the thorax is to support the powerful flight muscles
- T1 = first sternal rib
- Ribs are reinforced to transfer loads (uncinate processes attached scapular muscles to strengthen the rib cage).
How is the sternum important for flight in birds?
Describe how the muscles and tendons act for flight in birds?
The mechanism of flight in birds
/ a pulley system
Foramen triosseum = the junction between the clavicle, coracoid and scapular - passage for the tendon of the supracoracoides. muscle
Pectoralis muscle
superficial down beat
very large cross sectional area
attaches ventrally to the humerus
Supracoracoides M.
Deep up beat
Smaller cross sectional area
attaches dorsally to the humerus
Which sites on a bird are most suitable for injection or blood removal?
Avian injection sites
Intramuscular injections
- pectoralis muscle
Blood removal
- cutaneous ulnar (wing vein) preferable
Describe the adaptation of the pectoral appendicular skeleton in birds for flight?
Pectoral appendicular skeleton
Fusions of the bone in the wing
This acts to
- reduce muscle weight
- restrct the range of movement
- reciporacal apparatus
How
Fused carpometacarpus
- there is only two free carpal bones; the others are fused to the metacarpus
- the digits are reduced but this varies between different species
Describe the thoracic movement during respiration in birds ?
Describe the caudal axial fusions which occur in avian species?
Describe the modification of the hindlimb in birds for the purpose of flight ?
Hind limb fusion
Tibiotarsus
The tibia and the proximal row of the tarsus is fused
The is located between the proximal and distal tarsal bones
Tarsometatarsus
The distal row and metatarsal bones are fused
Define the pneumatic bones and how they are beneficial to birds?
What is the perching mechanism in birds ?
The perching mechanism
Key = the digital flexor tendon runs caudally to the tarsal joint before running to each digit.
This enables the bird to stay on a branch with minimal muscular effort
- when the bird lands on a branch its body weight forces flexion of the tarsus pushing down on the branch and tendon of the flexor muscles
- the effect is to flex all the digits which automatically grip the branch
Define a brood patch in birds ?
Describe the location and function of the Uropygial gland in birds ?
Describe the structure of a feather; including barbules, hooklets and the calamus?
In birds what is the Pterylae and Apteria?
Describe contour and filoplume feathers ?
6 primary differences
Describe how the respiratory system of birds is different to that of mammals ?
The respiratory system of birds differs from those of mammals by a number of very specific features
1. No vocal cords (syrinx which is the organ of voice production)
2. Complete tracheal rings
3. No diaphragm (no seperation between the thoracic and abdominal areas)
4. Unidirectional air flow (efficiency)
5. Pneumatic bones (extension of air sacs)
6. Sternal hinge (no lateral rib cage expansion)
Describe the role of the nasal cavity in birds?
The role of the nasal cavity in birds
- olfactory function
- particle filtering/ infiltration
- water economy
- heat exchange
The recover of exhaled saturated water vapour is crucial in arid zines or migratory birds. (may recover 50-70% of water in inhaled air 20-30 degrees)
Identify the infraorbital sinus of the head in birds ?
Infraorbital sinus
Fills the hollow space within the skull - opens into the nasal cavity and caudal nasal choncae
- olfactory function
- it is a paranasal sinus (maxillary) produces mucous
- open space under the skin in the lateral region of the upper jaw
- common site for infection with respiratory bacteria and viral pathogens
Describe the location of the syrinx and its function in birds ?
Describe the location and function of nasal salt glands in birds ?
Describe the structure of the oral cavity/ oropharynx in birds ?
The oral cavity of birds
Due to the loss of Glosso-palatine arch the oral cavity and pharynx form one cavity.
Larynx is a simplified structure
- four cartilages cricoid, procriccoid and paired arytenoid cartilages
THE THYROID AND EPIGLOTTIS ARE ABSENT
- function to prevent foreign material from entering the lower respiratory tract
Trachea
- ossified with complete rings
- overlapping
Choana - slit opening to the oral cavity
Palatine ridges - have caudally facing papillae, for food movement
Identify the structures used for respiration in birds ?
The respiratory system in birds
Lungs
- two small tucked dorsally against the ribs
- 1/10 equivalent to mammals
- parabronchi
Air sacs
- A very thin membrane lined sacs that duct the air to the lungs - difficult to see
- Cranial group, cervical, interclavicular and anterior thoracic
- Caudal group, posterior thoracic and abdominal
The function of air sacs
- ventilate the lungs
- regulate body temperature
- reduce the specific gravity of birds (relatively lighter for flight)
Describe inspiration and expiration in birds ?
Describe how the cardiovascular system of birds is different to that of mammals ?
Avian cardiovascular system
Avian hearts are relatively larger than comparable sized mammals
- typically 1-2.5% body weight (0.5% mammals)
- the right atrium receives blood from 2 cranial vena cava and one caudal vena cava
Further
- no trabeculae (smooth walledL
- simple valve flaps / with minimum valve protection reduced resistance
- large coronary arteries
- larger muscle mass than in mammals
- extensive bundle of HIS
What is unique about the venous system in birds compared to mammals ?
The venous system in birds
Birds have left and right jugulars which are much larger than in animals making them difficult to bleed.
Renal portal system
the blood from the hind legs of birds returns via the kidney
- this is in common with reptiles and amphibians
- cannect to caudal vena cava and caudal mesenteric vein through the liver
Describe the unique characteristics of the avian lymphohaematopoietic system ?
Avian Lymphohaematopoietic system
Accompany blood vessels but far less numerous than in mammals
The lymph nodes are absent
- there are lymphatic nodules in the wall of lymphatic ducts
- contains valves which controls the direction of flow
- some lymphatic nodules in the parenchyma of the organs eg liver, lung, pancreas and kidney
- GALT, BALT
Describe the primary lymphoid organs in birds ?
Primary lymphoid organs in birds
2 primary sites of lymphocyte production
Thymus
- cellular immunity (T cells)
- 3-8 irregular lobes down the neck
- structure similar to mammals, cellular imunity
Bursa of Fabricus
- Produces circulating antibodies (B cells)
- cloacal bursa ( dorso medial area of the proctodeum of the cloaca)
Describe the secondary lymphoid organs in birds ?
Secondary lymphoid organs of birds
Harderian gland
- in the eye sockets behind the eye
- accessory to the tear gland
- in birds = mucosal immunity acting on antigens entering via the eye
Spleen
- A rounded body on the right of the glandular stomach, relatively smaller then in mammals
Bone marrow - immune cells
Lymphatic nodules
- rudimentary (water birds) or absent
- mucosal lymphoid aggregates include 2 caecal tonsils
Desribe the topographical organisation of the digestive tract in birds ?
The digestive tract in birds
Describe the unique attributes of the oesophagus in birds ?
The avian oesophagus
Lies initially medial dorsal to the trachea - then moves to the right
- thin walled and foleded with mucous secretory cells
- can store food in some species (seed eaters, meat eaters have a dilation at the thoracic inlet known the the CROP).
- care must be taken during dissection as the crop may stick to skin
What is the function of the crop in birds?
The function of the crop
The crop transports food and is the site of physical digestion - soften, swell
- no chemical digestion
- some species the crop allows for the seperation of undigestable food items such as hair feathers in owls
- formation of crop milk in pigeons (rich in fat, protein) under the action of prolactin.
Describe the two divisions of the stomach in birds, and their function?
Avian stomach
Proventriculus (glandular part)
- a dilation almost indistinguishable from the oesophagus
- fine folds
- papillary projections into the lumen opening of glands - HCL + pepsin
- no pyloric spinchter
Ventriculus (Gizzard)
- muscular part
- a thick disscuss shaped muscular organ
- left of peritoneal cavity
- Heavy muscular layers - circular muscle (ratities may even use grinding stones)
- less well defined in fruit and meat eaters
Describe the intestines of avian species
Avian intestines
Small intestine
Caudal to the liver - tightly ball shaped
- on the right half of the abdominal cavity
- seperated from the abdominal wall by the caudal air sacs (thoracic and abdominal)
- paired blind ending caeca
- terminates via the colon
Colon
The colon originates at the junction of the ileum - colon rectum
- sphincter ileocolic junction empties into the rectum
In avian species describe the three divisions of the cloaca?
The three divisions of the cloaca (CUP)
Coprodeum
- the most cranial part
- no mucosal fold between the rectum and coprodeum
- way through for dung
Urodeum
- the middle part and the smallest
- way to the urogenital tract
- seperated by two parts; coprodeal and uroproctodeal folds
- the ductus deferens and oviduct orifice open into the urodeum
Proctodeum
- Situated between the uroproctodeal fold and the vent
- - in it opens the cloacal bursa and dorsal proctodeal glands (lubricant)
- some birds have male copulatory organs
Describe the avian urinary system?
Describe the avian male reproductive tract?
Describe the avian female reproductive tract?
Avian female reproductive tract
Although both sides of the reproductive tract develop the right quickly regresses
The left ovary
Found in the cranial part of the body cavity, and ventral to the left kidney
- during sexual maturity the ovary resembles a bunch of grapes with many follicles of varying size
- “stigma” at ovulation
The left oviduct
Egg production occupies the left dorsal quadrate of the body cavity - divided into five regions
Infundibulum = funnel part and tubular part
Magnum = longest and coiled; thick mucosa and forms the egg white
Isthmus = shortest and most narrow; forms the egg membrane
Uterus/shell gland = shell formation
Vagina = consist of a vaginal sphincter, spermatic fossulae or sperm gland which can store for many months
Describe three different methods to sex day old chicks?
As a Veternarian how would you go about handling an Australian amphibian?
Describe the anatomically unique features of the amphibian skeleton and skin ?
Anatomical unique features of the amphibian skeleton and skin.
Radioulna - the radius and ulna are fused
Tibiofibula - the tibia and fibula are fused
- the frog has four digits on the forefeet, and five digits on the hind feet
- the skin is highly permeable and not tightly adhered to the underlying structures (except skull)
Describe the unique anatomical features of an amphibian and sexual identification ?
Amphibian frog unique features
- short trachea
- 3 chambered heart
- renal portal system
- no teeth and very short GI tract
- the ureters open into the cloaca and store urea in the urinary bladder
- external fertilisation
Sex identification of frogs
- the males develop much smaller
- during the breeding season the male develops nuptial pads (to help them hold onto the female during amplexus), + the male has longer toes than the female
Describe the venipuncture sites and clinical studies of frogs ?
Amphibians
Venipuncture sites
- midline abdominal vein - runs along the ventral linea alba
- Vena orbatalis, blood collection via puncturing the vena orbatalis just above the jawline at the middle of the orbit.
Clinical case studies
- Chytrid fungus, lethargic, flex hindlimbs, skin discolouration
Describe the palatal valve ?
The palatal valve in crocodiles
The palatal valve consists of two compartments
- velum palati (ventral flap of the soft palate) distal compartment
- Gular fold - ventral compartment
- The function of the palatile valve is to seal the pharyngeal cavity while under water preventing aspiration.
Desribe the function of the Foramen of Panizza
Crocodiles Foramen of Panizza
Location between the left and right valve of the aortic arches
- function to alter the circulation when the animal is under water
- the left ventricle crosses allowing the heart to create more pressure (sharing deoxygenated blood around the whole body - not just the lungs).
Describe the unique anatomical features of crocodiles ?
Unique anatomical features of crocodiles
Septum post hepaticum
- diaphragm like muscle
- seperates the thoracic and abdominal cavities
- no urinary bladder (colon can hold large amounts of urine and water)
- 4 chambered heart
- Foramen of Panizza
- Palatal valve
Describe the venipuncture sites in crocodiles and clinical studies ?
Crocodiles
Venipuncture sites
- Ventral coccygeal vein (blood draw from lateral side)
- Occipital sinus (lateral aspect of head and neck)
Clinical cases
- Integumentary disease (most significant disease of commercial crocs)
Describe how a Veternarian should go about handling a fresh water turtle?
Descrribe the unique features of freshwater turtles?
Anatomical unique features of freshwater turtles
Describe the venipuncture sites of fresh water turtles?
There are several possible sites for venipuncture in fresh water turtles
- The left jugular vein
- Subcarapacial sinus
(the head may either be extened or pushed back into the shell) - Brachial vein
- Dorsal coccocygeal vein
Clinical case studies
- broken shell
- foreign object
Describe how a Veternarian should handle an sea turtle?
Describe the unique anatomical features of sea turtles?
Unique anatomical features of sea turtles
Carapace = Dorsal shell; vertebral and rib bones (rib and pleural bne) sit upon peripheral bone.
Plastron = ventral shell
- have flippers but still contain 5 digital bones
- no teeth
- oesophagus contains many papillae/ spikes which makes endoscope work problematic
- Salt glands 80% of head region (small brain)
- Renal portal system kidney
What are the main venipuncture sites in sea turtles ?
Describe the unique anatomical features of all reptiles?
Reptiles
12% of worlds reptile population in Australia, abundantly in the centre and the North of Australia.
Respiratory
- Reptiles are predisposed to lower respiratory tract infections due to their unique lung structure and lack of a diaphragm.
Renal portal system
Allows blood from the caudal aspect of the body to circulate through the kidneys before reaching the systemic circulation.
- this may cause a problem in drug administration (nephrotoxic affects / or no affects at all).
Describe the best practice for snake handling?
Describe the unique anatomical features of snakes?
Snakes
All they lack
- No eyelid, compensated by brille is a transparent structure which covers the eye
- No mandibular synthesis
- No vocal cord, hiss by forcing sound through the glottis
- No sernum
Jacobson organ
- the toungue is a chemosensory structure which is inserted into the Jacobson organ (located roof of buccal cavity)
Fangs
- in venomous snakes the venom gland is a modified salivary gland
Snake teeth are pleurodentic - replaced throughout life
Describe how you could venipuncture a snake and common potential diseases ?
Snakes
The venipuncture sites
1. Ventral coccygeal, caudal tail vein (midline ventral vein
2. Cardiac puncture (requires euthanasia) palpation and doppler probe. Immobilise the heart manually by placing one or two fingers cranially and caudally.
Clinical case studies
- Burns
- Dysecdysis (difficulty with shedding)
- Retained specticles
- Subspectacular abscess
Describe how a veternarian should handle reptile species?
Describe the anatomically unique characteristics of Lizards ?
Lizards
- lizards will shed their skin (incomplete)
- Chromatophores
- paired abdominal testis and hemipenes on the ventral aspect of the base of the tail and caudal to the vent
- 3 chambered heart
Describe the venipuncture sites of reptiles and common clinical problems ?
Lizards
The venipuncture sites
1. Ventral coccygeal vein
(take care in the male entry site must be distal to the hemipenes)
2. Jugular vein
3. Ventral abdominal / Coelomic vein
Clinical case studies
- wounds
- Nanizziopsis barbate (primary fungal infection in Australia)
- strictures of the digital skin.
Describe how a Veternarian should go about handling a tortoise?
Describe the various anatomical differences between turtles and other reptilians ?
Tortoises
Skeletal
- comprised membranous-bone covered by scutes which are formed by the epidermis (keratinised layers)
- no nasal sinus
- tracheal rings complete
- pleuroperitoneal membrane (pseudodiaphragm)
- unable to expand chest, so develops strong trunk musclesto help expand and contract lungs
- no teeth
Body
- 3 chambered heart
- flat and lobulated kidneys excrete uric acid to urodeum + travels to the urinary bladder
- single penis phallus which retracts into the coelomic cavity (not involved in urination)
- testes and ovaries are located inside the coelomic cavity
Describe the venipuncture sites of the tortoise ?
Describe the pectoral girdle and front limb structure in monotremes ?
Monotremes
The pectoral girdle
- Has two clavicles, T shaped interclavicle, scapular and two broad coracoids
- the pectoral girdle provides a sturdy base for digging and action of the forelimbs
- the coracoids articulates with the presternum and scapula to form the glenoid cavity
- the glenoid cavity is deep and orientated laterally, this accomodates the horizontally orientated humerus
The forelimb
- humerus rotates around its axis rather then moving back and forth
- ulna elongated olecranon which extends proximal to the elbow
- the proximal end of the olecranon has a spade like shape
- the radial carpal bone and intermediate carpal bone are unitied
Describe the structure of the hindlimb and pelvic girdle in monotremes ?
Monotremes
Pelvic girdle
- comprised of the ilium, ischium and pubic bones
- the acetabulum has a central foramen
- has a pair of epipubic bones project the cranial border of the pubis (extra abdominal support)
The hindlimb
- The femur is short with flattened extremeties and its head inserts horizontally to the acetabulum
- femur rotates along its access in locomotion
- large ossified petella
- tibia and fibula of equal size and are rotated caudally so the pes is rotated outwards
- proximal end of fibula = elongated proximal process
Describe the uique external anatomical structures of the platypus ?
Platypus
Streamlined body compressed dorsoventrally covered in fine dense water proof fur
Frontal shield and bill
- dorsal positioned nostrils + soft leathery pigmented skin
- mechanoreceptors and elctroreceptors
Muscular groove
- (located posterior to the dorsal shield) houses the eyes and ears, closure of which shields the eyes and ears completely while underwater.
tail = rudder
forefeet webbed
Hind feet partially webbed
Describe the sexual differences between male and female platypus ?
Platypus
Male
- hollow kertinous spur on the medial tarsus - which connects via a venom gland on the dorsal thigh (gland size is androgen dependant)
- paired abdominal testis (body temp 32C)
- sperm - urogenital sinus - penile urethra (only transports sperm)
- bifid glans
- penis lies within a preputial sac in the caudal urogenital sinus ventral to the cloaca.
Female
- paired ovaries only the left is functional
- large follicles project from the surface of the ovary
Each oviduct leads to a seperate uterus which then open into the urogenital sinus
- lays 1-3 eggs
- no teats; areolae milk patches
What is the pelvic rete mirabile ?
The pelvic rete mirabile
Enables the platypus to thermoregulate in the aquatic environment
- is an extensive network of parallel arteries and venous vessels which supplies the muscles the hindlimb
- forms a countercurrent heat exchange system serving to restrict heat loss.
Describe the unique features of the digestive system in the platypus ?
Digestive system platypus
Dentition
- young platypus leaving the nesting burrrow reabsorbs the teeth
which is then replaced by keratinous grinding pads (grow continuously to offset wear)
- check pouches, specialised tongue and grinding pads
Stomach
- No digestive enzymes
- cornified stratified epithelium to grind prey
- transit 5 hours
Urinary
- kidneys smooth bean shaped and produce urea
- empty into common urogental sinus with the bladder on the ventral surface
Describe how a Veternarian should go about physical restraint of a platypus ?
two sites
Describe the possible venipuncture sites of the platypus ?
Describe the unique external features of the echidna ?
The unique external features of an echidna
Echidnas are adapted well to digging, locating and consuming ants
- quills are under neuromuscular control and can be erected in defence or used to grip surroundings
Panniculus adiposis
- skin is thick with a fat storage layer the panniculus adiposes, underlying this is the panniculus carnosus.
Panniculus carnosus
- has the embedded roots of the spines and allows for individual control of the spines
- thicker dorsally then ventrally
- 1/3 body mass
- responsible for the echidna’s ability to roll into a ball and wedge itself into crevices
Describe the importance of the sensors in the echidna ?
Describe the sensors of the echidna
Cylindrical snout
- elongation of upper and lower jaws, cartilage and soft tissue
- mechanoreceptors, electroreceptors and olfactory receptors (enormous area of olfactory epithelium)
- hundreds of mucous secreting glands which act to improve the sensitivity to electrical signals
- mechanical probe
Ears and eyes
- located at the base of the snout
- cartiliginous pinna of the external ear embedded in adjacent skin + muscle
- ear opening vertical axis - tortuous ear canal which has 3 right angle turns
Describe the unique features of the musculoskeletal system in echidnas ?
Musculoskeletal system in echidnas
The mandibles
- delicate weakly fused at symphysis and articulate loosely at the mandibular fossa
- mandble rotates medially to mouth = small opening
- when food items are too large they will break them up with their snout
The skekeletal structure
The forelegs are shorter and more muscular than the hindlegs
- solid pectoral girdle clavicles, interclavicle, scapular and coracoids
- pes is narrower than the manus
- digit one reduced, digit two elongated claw for digging and grooming
- all males (some females) crural spur non venomous
Describe the unique characteristics of the digestive system in the echidna ?
Echidna digestive system
Dentition
No teeth - elongated tongue with sticky saliva (sublingual glands)
- saliva assist with mastication and prehension of food
- Tongue cavernous vascular network erectile
- extend atleast 18cm, can be protruded and retracted atleast 100times per min
- food is grounds backward keratinous spines at the base of tongue and hard palate
- the mandibular salivary glands are palpable on the neck
Stomach
monogastric disgestive system
- no secretiry gland cornified stratified epithelilum to grind invertebrate food
Renal system
- paired smooth bean shaped kidneys empty into common urogenital sinus
- the bladder sits on the ventral wall of the urogenital sinus
Describe the unique features of the male and female echidna ?
Echidna
Female
- oviparous
- paired ovaries and both are functional
- large follicles project from the surface of the ovary
- female incubates her eggs within a pouch
- each oviduct leads to a seperate uterus which then open into the urogenital sinus
Pouch
- sweat galnds only found in pouch area
- no permanent pouch both sexes may contract abdominal muscles to give the appearance of a shallow pouch
- milk areolae
Male
- paired ovoid abdominal testes
- testes significantly increase in size during the breeding season
- sper - ductus deferens - urogenital sinus then penile urethra
- the penile urethra only used to transport sperm
- penis can retract into the preputial sinus while not in use
- the glans penis is divided into four bulbous portions
- bulbo urethral glands are well developed
Describe how a Veternarian should act to restrain a echidna ?
Echidna restrain
May be difficule - strength, quills, ability to curl into a tight ball
- life with gloves or several layers of thick towel
- Ungloved hands - palms facing upwards work your hands underneath the abdomen (echidna may curl around your hands)
- The hind feet may be grasped
Describe the venipuncture sites of an echidna ?
Describe the unique characteristics of the musculoskeletalsystem of marsupials ?
Musculoskeletal system of marsupials
- The ossified patella dose not exist (except bilby, banndicots)
- epipubic bones extend from the cranial aspect of the pubis
- the second and thirds digits are syndactylus (united/webbed)
- paired claviacles
Marsupials are divied into two groups based upon their dentition
Marsupials have diciduous teeth, aprt from third molar which degenerate before eruption
Polyprotodonts
- carnivores, ornivores
- many incisors
Diprotodonts
- majority herbivores
- two lower incisors
- macropods, koalas and gliders
Describe the unique features of the immune system in macropods ?
Immune system of macropods
There is no lymphoid tissue present at birth in macropods and the neonate is compromised
- passive transfer of antibodies through the milk
- antibodies can be readily absorbed through the gut epithelium
- most species reach immune system maturation approximately halfway through pouch life
- no superficial lymph nodes are palpable in healthy macropods (except koala inguinal, axilliary and mandibular lymph nodes may be palpated)
- popliteal and subiliac lymph nodes are absent
Describe the unique features of the male and female reproductive tract in marsupials ?
The reproductive system is similar in all Marsupials
Female
- paired ovaries surrounded by the infundibulum leads to two seperate uteri
- seperate crevices toe the vaginal cal de sac cauadal openings to the urogenital sinus
The lateral vaginas are seperated along their length by the median vagina
- semen depositied lateral vagina, foetus passes through the medial vagina
- diffuse epitheliochorial choriovitelline placenta
Male
- lack teats
- paired testes and epididymis in prominent pendulous scrotum
- strong cremaster muscle
- accessory sex glands = large prostate and bulbourethral glands
- form seminal plug in the female urogenital sinus
Describe the unique external general characteristics of macropods ?
Macropods
Heavily muscled hind limbs, narrow shoulders and long tapering tail
- thin skin with a large subcutaneous blood supply which allows through evaporative cooling through licking
- may lick arms to assist cooling
Eccrine galnds
- only found on hairless surfaces of the paws and feet
Apocrine (scent gland)
- found all other their body
Care when handling in larger kangaroes sweating is only initiated during exercise, once stoped sweating stops (even while body temp still elevated).
Describe the musculoskeletal system in macropods ?
Musculoskeletal system in macropods
Vertebral formula C7, T13, S2, Ca 21-25
- pelvis = centre of mass
- elongated bones and powerful fourth digit
- second and third digits are syndactyls very small and used for grooming only
- calcaneous load bearing
- the fibula is distally reduced to a thin splint
- tail non prehensile
- movement of the tarsus is purely flexion / extension
Pentapedal tail
Describe the unique attributes of the gastrointestinal system in macropods ?
Digestion macropods
Atlanto occipital articulation is very flexible allowing the head to remain horizontal wether the neck is vertical or horizontal
Mandibular synthesis is not fused - and flexible which allows the lower incisors to spread apart and shear against upper incisors
Dentition -
- large pair of lower forward facing incisors fits with arc of upper incisors and presses against the pad on the rotral hard palate
- unfused mandibular synthesis
- large diastema
- molar regression, migrate forward through out life
Digestion
Foregut fermenters, large sacculated stomach divided into forestomach and hindstomach
- sacciform and tubiform stomach
- glandular epithelium secretes mucous
- fermentation short chain fatty acids, detoxification and produces vitamin B
Describe the physical restraint of macropods ?
Describe the common sites for venipuncture in macropods ?
Describe the unique musculoskeletal system of the koala ?
Koala vertebral formula C7 T11 L8 C3 Ca7-9
- naturally curved spine
- cartiliginous pad sits over the end of the spine
- strong thigh muscles provide the majority of climbing strength
- deep bow in the radius
- five digits manus, with digit one and two opposed
- pes digit one opposed + digit three and two are fused
- the hip joint is shallow and the hip flexes the knees rotate externally
- cartilaginous patelloid
- two epipubic bones
Pectoral girdle
The paired clavicles articulate with acromion of the scapular and first sternal element provides a semi rigid structure.
Why is it difficult to incubate a koala ?
The koala has a elongated soft palate and pharynx - making it difficult to intubate
NO NASOGASTRIC INTUBATION - complex arrangment of nasal sinuses
- intact mediastinum
Describe the unique gastrointestinal features of the koala ?
Koala Gastrointestinal
Koalas are monogastric hindgut fermentors
- largest caecum of any mammal relative to body size (upto 2m)
- loops of caecum and colon full the entire space of the ventral portion of the abdomen
- no omentum present
- the linea alba is broad and almost translucent
Describe as a veternarian how you would go about physically restraining a koala ?
Physical restraint koala
From behind grasp wrist face koala away from handler
May grasp the wrist then the ankles - so the koala is restrained in a sitting position facing away from the handler
After lifting it is good practice to support the animal against your body or another object
- use towels, bags, hessian bags to calm the animal
